
def avg_sqr(data_list):
    data_num = len(data_list)
    data_square_num = sum([i*i for i in data_list])
    return pow((data_square_num/data_num),1/2)

if __name__ == '__main__':
    sample_list = [50,60,75,85,100,30,48]
    print(avg_sqr(sample_list))